Signments



( No Model.)

W. B. POTTER. METHOD CE AND MEANS ECB. EXTINGUISHING ELECTRIC ARCS.

Patented Aug.6,1895.

.UNrTED STATES PATENT OFFICE.

WILLIAM B. POTTER, OF SCHENECTADY, NEW YORK, ASSIGNOR, BY MESNE- AS- SIGNMENTS, TO THE GENERAL ELECTRIC COMPANY, OF SAME PLACE.

-METHOD OF AND MEANS FOR EXTINGUISHING ELECTRIC ARCS.

SEECIFIGATION forming part of Letters Patent No. 543,892, dated August 6, 1895.

Application tiled November 30, 1891i. Serial No. 530,414. (No specimens.)

T @ZZ whom, t may con/cera:

Beit known that 1,*WILLIAM B. POTLER, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Methods of and Means for Extinguishing Electric Arcs, of which the following is a specification.

My invention relates to methods of and ro means for extinguishing electric arcs, and

has for its object to provide a method of extinguishing arcs without permitting their extension to undue dimensions or their persistence for any length of time, for which 1 5 purpose I provide a blow-out, preferably magnetic in character, tending to disrupt the arc by, magnetic lines of force, and I also inclose the terminals at which the arc is likely to be formed within a chute of insulating material zo refractory in its nature.

It is well known that the extinction of an arc between the terminals of an electric circuit may be accomplishedl by means of the lines of force from a magnet, either a permanent magnet or one electrically excited, pro.

vided the path of the arc and the lines of force of the magnet are at a substantial angle with one another. It is also woll known that an electromagnet or other magnet so arranged 3o that an are tends to pass in a direction parallel to the lines of force kbetween its poles has comparatively little effect upon it.` I have discovered that the presence of exposed metal near the terminals is deleterious to the extinction of the arc, even although the metal mayy be magnetic and be energized by the passing current. Unless the lines of force emanating from the metal are at a substantial angle to the path of the arc, the metal 4o may itself form a conducting terminal having but little power to extinguish the arc, which may then pass along it to the end of the path formed thereby. I have also discovered by experiment that by inclosing the arc in a chute of refractory non-conducting material I may so confine i-t that the magnetic field will always act in the direction best adapted to extinguish it. Where the arc becomes of undue length, as it may by passing on to metal adjacent to the terminal, it may in ordinary practice be driven from the magnetic field, or from the part thereof which is strong enough to extinguish it, without being blown out. I have found that Where the parts adjacent to .the terminals are made of metal the arc will persist for a very considerable time and will become of considerable length, whereas by the practice of my invention it is extinguished in much less time and while still quite short,

so that the undue waste of current and en- 6o ergy and (which is of far more importance) the destructive effect are thereby greatly reduced or practically prevented.

The accompanying drawings show conventional embodiments of my invention in two different forms, Figure I representing a plan view, partly in section, of my invention applied toa lightning-arrester. Fig. 2 shows an end elevation, partly in section, of its application to a fuse; and Fig.3 is a diagram illus- 7o trating the'principlesot' the invention.

Nothingin the illustrations employed is to be taken as limiting my invention to any particular combination of apparatus, as its application is universal to all cases Where an arc is to be extinguished. Although a lightning-arrester and a fuse are the forms of apparatus in which the are is most likely to occur, yet it is manifest tliatcontacts of other forms may also render the application of my 8o invention desirable, 'and all suchA apparatus I aim to embrace Within the scope of the claims.

Referring by letter, A is the chute, open at both ends, to which I have referred in my statement of invention, which is preferably made of some insulating material refractory in its nature, such as slate, although it may be made of any other suitable material substantially fireproof, as of molded insulation or of mica or any other insulating material 9o capable of resisting for a short time the heat of the are.

B B are the poles of an electromagnet provided'with a coil C and, in the case of Fig. l, connected in circuit from the line a to ground G, the circuit passing across the lightningarresterv terminals D I). These terminals are ofthe form commonly employed in such apparatus, having a space between them closely approximated at one end and widening at the 10:5 other, so that as the arc stretches over a greater space it` will be followed up and forced outward by the magnetic field. By removing the conducting material of the electrode in massa this way the resistance to the arc is increased and its breaking facilitated. The windingof the coil C is in such a direction as to compel the arc to travel to the wider part of the space; but this is well understood in the art and forms no special part of my invention.

In Fig. 2 I show substantially the same combination of apparatus; but in that figure the terminals D D are connected by a thermal cut-out or fuse E, which is situated in the circuit which passes from the line ct across the fuse E to the line l), forming the continuation of the circuit.

The operation of the devices just illus` trated is further explained by reference to Fig. 3, although it might be sufficiently apparent from the statement of invention and description. In this figure I have illustrated diagrammatically the action as exemplified by experiment. The parts and their relation are the same as in the other figures, cxcept that the progressive paths of the arc as it approaches nearer and nearer to the point of breaking are shown by the dotted lines (Z CZ, tbc. It will be seen that each of these lines is longer than the one beneath it, but that for the greater part of their length they are substantially transverse to the lines of forceff, dsc., which pass in the direction of the arrows and are generated by a magnet. (Not shown in the drawings for clearness of illustration.) When, however, the arc be` gins to travel along the sides of the insulating-chute A, the resistance becomes so great that it is almost immediately ruptured, as already pointed out, and this rupture is greatly facilitated by the fact that its path is substantially coniined to the part of the magnetic field having the greatest energy.

The method of operation is therefore inclosing an arc which is to be extinguished or which may be formed between the terminals o t' an electric circuit in a chute open at both ends, so that the arc is limited in its path to a direction transverse to the lines of force tending to disrupt it, while at the same time the powerful currents of air set up bythe breaking of the arc and its forcible passage through the atmosphere tend to assist its rupture. This latter action to which I have referred is extremely energetic, and I have found it of great assistance in the rupture of the arc. I have found that if one end of the chtite be closed the duration of the arc is materially extended and the consequent damage may be very great.

By the practice of my invention I have been enabled to rupture Without difficulty and with certainty the arc caused by a current of tive hundred and fifty volts potential and .four thousand four hundred ampres in volume, or more than three thousand two hundred horse-power. The rupture was effected before the fuse carrying the current had burned away to any great extent, the narrowest point of the gap being only threesixteenths of an inch, and the metal was blown out of the chute with considerable force, being projected upward more than forty feet. 4

As a means of testing the etlicacy of my invention, I have placed the magnet and the terminals at the base of a chtite such as I have described, and reversed the direction ot winding of the magnet, so that the magnetic field tended to force the arc away from the chute, and in such case the arc was blown entirely out of the magnetic field, except at points so near the terminals as to have but little effect upon it, and persisted for a very considerable length ot' time without being ruptured, whereas, when the are was blown into the chtite, it was almost immediately ruptured, as already pointed out.

Many forms of apparatus may, of course, be devised embodying my invention and embodying the method herein pointed out, and minor variations may be made therefrom without affecting its spirit; but all such forms of apparatus and variations I aim to embrace in the claims.

What I claim as new, and desire to secure by Letters Patent of the United States, is-d l. The method of extinguishing an electric arc, which consists in restraining the path of the arc to a line of direction substantially transverse to the lines of force from an are` disrupting means tending to extinguish it.

2. The method of extinguishing an electric arc, which consists in coniining the path of the arc to a line of direction substzmtially transverse tothe lines of force of an arc-rupt uring magnet.

3. The method of extinguishing an electric are, which consists in inclosingthearc within a chute of refractory insulating material closed at the sides and open at both ends, arranged to cooperate with other arc-extinguishing means.

4. The method of extinguishing an electric arc, which consists in inclosing the arc within a chute of insulating refractory material closed at the sides and open at both ends, and providing a magnetic field within the chtite.

5. In combination, terminals at which an arc may be formed, a chute of insulating refractory material closed at the sides and open at both ends and inclosing such terminals, and an arc'extinguishing means co-operating with the chute.

G. In combination, terminals at which an arc may be formed,l an electro-magnethaving its poles closely approximated to such ter minals, and a chute of refractory insulatingr material inclosing the terminals, the chute being` open at both ends and closed at ille sides.

In witness whereof I have hereunto set my hand this 28th day of November, ISD-1;.

WILLIAM B. PO'LTER. Witnesses:

B. B. HULL, A. F. MACDONALD.

IIO 

